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    <title>ShellCheck: SC2253 – Use `-R` to recurse, or explicitly `a-r` to remove read permissions.</title>
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    <h1>SC2253 – ShellCheck Wiki</h1>
    <a href="https://github.com/koalaman/shellcheck/wiki/SC2253">See this page on GitHub</a>
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    <h2
id="use--r-to-recurse-or-explicitly-a-r-to-remove-read-permissions">Use
<code>-R</code> to recurse, or explicitly <code>a-r</code> to remove
read permissions.</h2>
<h3 id="problematic-code">Problematic code:</h3>
<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="SC2253.html#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="fu">chmod</span> <span class="at">-r</span> 0700 dir</span>
<span id="cb1-2"><a href="SC2253.html#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="fu">chmod</span> <span class="at">-r</span> file</span></code></pre></div>
<h3 id="correct-code">Correct code:</h3>
<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="SC2253.html#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="fu">chmod</span> <span class="at">-R</span> 0700 dir</span>
<span id="cb2-2"><a href="SC2253.html#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="fu">chmod</span> a-r file</span></code></pre></div>
<h3 id="rationale">Rationale:</h3>
<p>Many tools use <code>-r</code> for recursive operation, but in
<code>chmod</code> this removes read permissions.</p>
<p>If you wanted to change permissions recursively, change the flag to
<code>-R</code>. If you wanted to remove read permissions, consider
using <code>a-r</code> explicitly to make this more obvious.</p>
<h3 id="exceptions">Exceptions:</h3>
<p>If you're using it correctly and don't mind the potential for
confusion, you can save a single character by ignoring this warning.</p>
<h3 id="related-resources">Related resources:</h3>
<ul>
<li>Help by adding links to BashFAQ, StackOverflow, man pages, POSIX,
etc!</li>
</ul>
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    <p style='font-size: 80%'><a href="../index.html">ShellCheck</a> is a static analysis tool for shell scripts. This page is part of its documentation.</p>
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